基于数值模拟的泥石流拦挡坝群布局优化  

Layout Optimization of Debris Flow Check Dam Cascade Based on Numerical Simulation

作　　者：王浩[1] 张金涛 代林 王全才[2] 王继华 WANG Hao;ZHANG Jintao;DAI lin;WANG Quancai;WANG Jihua(School of Civil Engineering and Architecture,Henan University,Kaifeng 475000,Henan,China;Institute of Mountain Hazards and Environment,Chinese Academy of Sciences&Ministry of Water Resources,Chengdu 610213,China;Institute of Natural Resources Monitoring and Comprehensive Land Improvement of Henan Province,Zhengzhou 450000,China)

机构地区：[1]河南大学建筑工程学院,河南开封475000 [2]中国科学院、水利部成都山地灾害与环境研究所,成都610213 [3]河南省自然资源监测和国土整治院,郑州450000

出　　处：《山地学报》2024年第6期805-815,共11页Mountain Research

基　　金：河南省科技攻关项目(232102321012,242102321007)。

摘　　要：在工程实践中,常采用拦挡坝群协同布局防治泥石流灾害。泥石流翻越首坝后,其运动状态会发生显著变化,次级坝体的受力状况以及整体的防治效果,均会受到坝体间距和坝体结构的重要影响。前期研究关注单一坝体,对坝群间距如何影响坝体承载模式及防治效果尚缺乏认识。本文基于野外实地勘察,利用ANSYS-Fluent的流固耦合模型,模拟在泥石流冲击作用下,多级拦挡坝的不同间距、坝型与坝体应力之间的关联。结合RAMMS的Voellmy流变模型,对二郎山后山泥石流进行了多级拦挡坝设立间距的模拟分析。从坝体静力和防治效果两个方面,深入探讨了坝体间距的影响。研究结果表明:(1)在空库过流达到稳定流动状态后,泥石流浆体的总压力呈现出上小下大的层状分布特征。(2)与拱形坝相比,矩形坝所产生的应力和位移相对较小。首道坝体所承受的应力和位移均小于次级坝体。(3)设立两级拦挡坝对泥石流运动起到明显的调控作用。随着两级坝体间距不断扩大,拦挡坝所受位移与应力发生波动。当间距80 m时,两级拦挡坝的应力与位移均达到最大值,为最不利间隔。(4)随着坝体间距增加,泥石流最大堆积高度与流速呈现先增大后减小的变化趋势。(5)当二郎山坡面泥石流拦挡坝的设立间隔为40 m、100 m、120 m时,防护效果较为理想。研究结果对多级泥石流拦挡坝的优化设计具有借鉴意义。In engineering practice,a check dam cascade is arranged in a coordinated layout to prevent massive debris flow disasters.After a debris flow overtops the first dam of a dam cascade,its movement pattern undergoes significant changes,with the stress state in the second-level dam and the overall prevention efficiency being both greatly affected by the distance between dams as well as dam structure.Previous studies only concerned about the behaviors of a single dam in debris flow control design,lacking knowledge of how the spacing between dams affects their load-bearing patterns and prevention effectiveness.In this paper,based on field investigation,a fluid-solid coupled model in ANSYS-Fluent was utilized to simulate the correlation among different spacings,types and stresses of multi-level check dams under the impact of debris flow.Combined with the Voellmy rheological model in RAMMS,a thorough analysis of the spacing of the dams was exemplified by a real debris flow gully,located at backslope of the Erlang Mountain,Sichuan,China.The influence of dam spacing was discussed from two aspects:dam body static force and prevention effectiveness.(1)After achieving a stable state of overflow in dam reservoir,the total pressure of debris flow slurry on dam exhibited a laminar distribution with higher pressure at bottom and lower pressure at top.(2)Compared with arched dams,the rectangular dam generated relatively smaller stress and displacement.The stress and displacement endured by the first-level dam body was both less than those in the secondary-level dam body.(3)The establishment of a two-level check dam cascade provided a significant regulating effect on debris flow movement.With continuous expansion the spacing between two dam bodies,the displacement and stress in the second-level dam fluctuated.When the spacing was 80 m,the stresses and displacements in the two-level check dam both reached the maximum value,indicating the most unfavorable spacing.(4)With the increase of dam spacing,the maximum accumulation height and

关 键 词：泥石流 拦挡坝群 数值模拟 优化设计 

分 类 号：P642.23[天文地球—工程地质学]